Method and apparatus for counter current liquid-liquid extraction

ABSTRACT

A liquid-spraying system comprises an elongated tubular conduit means adapted for the flow of liquid therethrough, a tube wall of liquid-tight, elastically resilient material, liquid feeding means connected to one of the ends of the conduit means, closing means for at least substantially closing off the other end of the conduit means, and a large number of perforations of substantially circular cross sectional area through the tube wall and leading from the conduit interior to outside of the external tube wall surface. 
&lt;??&gt;The tube wall is made of a liquid-tight, elastically resilient material which is non-swelling in contact with water of a temperature of 60 DEG C or higher and with organic extraction solvents, and wherein the perforations are uniform and have an outlet of at most about 0.8 mm&lt;2&gt;, being small enough to produce capillary forces between water and the material of the surrounding tube wall sufficient to substantially prevent water filling the conduit interior from flowing out of the perforations while the water in the conduit interior is under ambient pressure, but being sufficiently large and of such configuration as to permit ejection of the liquid jet substantially free from trickling, when the liquid in the conduit interior is under excess pressure at least of the magnitude derived from a water main.

This is a division of application Ser. No. 06/852,633, filed 16 April86, now U.S. Pat. No. 4,749,130which in turn is a continuation in partof application Ser. No. 06/523,175 filed on Aug. 15, 1983 and nowabandoned.

BACKGROUND OF THE INVENTION

This invention relates to liquid-spraying systems comprising

(a) an elongated tubular conduit means adapted for the flow of liquidtherethrough,

(b) a tube wall of liquid-tight, elastically resilient material,

(c) liquid feeding means connected to one of the ends of the conduitmeans,

(d) closing means for at least substantially closing off the other endof the conduit means, and

(e) a plurality of perforations of substantially circular crosssectional area through the tube walls and leading from the conduitinterior to outside of the external tube wall surface.

It will be understood that the tubular conduit means, e.g. a hose, hastwo ends and an elongated conduit interior extending from one end of theconduit means to the other, that the tube wall surrounds the elongatedconduit interior and has an external and an internal tube wall surface,and that the liquid feeding means are adapted for causing liquid to flowinto the conduit interior.

The present application is a division of application Ser. No. 06/852,633filed Apr. 16, 1986 and now U.S. Pat. 4,749,130 which in turn is acontinuation-in-part of application Ser. No. 06/523,175 filed Aug. 15,1983 and now abandoned.

More particularly, such shower system comprises

(a) an elongated tubular conduit means adapted for the flow of liquidtherethrough, having two ends and an elongated conduit interiorextending from one end of the conduit means to the other, and being ofthe configuration of a helix having a central helix axis and confiningan internal helix space,

said helix being adapted for positioning with its axis disposedsubstantially vertically, the diameter and height of the helix beingsuch as to house a person standing or sitting within the internal spaceof the helix of vertically disposed helix axis, which conduit meanscomprise:

(b) a tube wall of liquid-tight, elastically resilient material, beingnon-swelling in contact with water of a temperature of 60° C. or higherand with organic extraction solvents, which tube wall surrounds theelongated conduit interior and has an external and an internal tube wallsurface,

(c) one end of the conduit means is adapted for connection to a sourceof bath water of adjustable temperature,

(d) closing means for at least substantially closing off the other endof the conduit means,

(e) a plurality of substantially capillary-active and uniformperforations preferably of substantially circular cross-sectional areathrough the tube wall leading from the conduit interior to outside theexternal tube wall surface, which perforations are substantiallyuniformly distributed.

This type of shower system has been described in the French patent toS.A. dite SAEREXI, of Calvados, France, having Publication No.2,032,014. This shower system is also provided with suspension meansconnecting the windings of the tube constituting the helix at a givenspacing and support means from which the suspension means depend andwhich can comprise a system of crinoline-like rings.

However, when using tubes having a conventional type of perforation in agiven configuration and arrangement of the holes in the tube wall, ithas been found that the user will not be able to suffer, over aprolonged period of time, i.e. several minutes up to 5 or even 10minutes, water jets having a temperature of more than 40° C., andusually only about 38° to 39° C., i.e. one or two degrees above normalbody temperature.

When taking a normal shower, a water temperature above 40° C. (104° F.)is barely supported by the user The shower also has a stimulating effecton blood circulation, however the bundle of water impinges in arelatively limited area of the user's body and still leaves areas of theskin unattained which permits the user to register temperaturesdifferences which cause such person to stop the shower, usually withouthaving reached transpiration. On an average, a shower is used by aperson for less than 3 minutes.

Installations as can be found in spas, which permit thermal baths orprolonged showers, require costly apparatus and personnel.

Moreover, it is difficult to avoid a pressure drop over a distance ofseveral meters and maintain a uniform ejection of liquid from so manynozzles when the nozzle openings have been punched or pierced in suchmaterial as sheet iron or the like metal, when the available pressure isin the order of water pressure from the city main. The longer thedistance from the pressure source and the larger the number of nozzles,the more difficult does it become to maintain a relatively uniformejection of the water.

OBJECTS AND SUMMARY OF THE FIRST INVENTION ASPECT

It is a principal object of the first aspect of the invention to providea tubular, perforated enveloping shower of the above-described SAEREXItype in which a user is exposed to a therapeutical effect as achieved ina sauna.

In order to attain a sauna-like effect it must be borne in mind that thebody of a person taking a bath in a sauna is exposed to a mixture ofsteam and air having a temperature ranging from 70° C. to close to 100°C. (160° to 210° F.), with short interruptions for a period of 20 to 40minutes. This sauna bath improves blood circulation and istherapeutically beneficial in other respects.

It is another object of a first particular aspect of my invention toprovide a liquid-spraying system which is useful in hydrotherapy, whichcan be used at low pressure rates such as prevail e.g., in the watermain, and which has hydrotherapeutic effects similar to, but morereadily supported and for longer periods than a hot shower and at leastas well as a sauna bath.

It is therefore a further object of the invention to provide a showerinstallation, as an alternative to a sauna, which permits a person touse water above 40° C. without unpleasant effects and for a periodsufficiently long to cause perspiration of the user's body.

I have found that these objects can be attained in a helical shower asinitially described having, in combination, the following featurescharacterizing the invention:

(i) the perforations have an outlet size in the order of 0.8 mm², andare preferably circular, having a diameter the order of 1 mm, i.e. offrom about 0.8 to 1.2 mm,

(ii) the length of the spraying zone of the hose is from about 10 to 20meters,

(iii) the number of perforations is about 150 to 400 over the entirelength of the helix, the distance between two adjacent perforationsbeing constant and in the range of from 2.5 to at most 10 cm, andpreferably from about 5 to 7 cm,

(iv) the internal width of the tube is about 15 mm and the perforationsare located in a substantially straight row on the inner side of thetubular conduit and are adapted for directing each a fine liquid jetradially toward said helix axis at the respective level of theperforation above the ground.

A preferred embodiment of the shower system according to the inventionhas at least one and preferably all of the following features:

(1) the tube wall material is a thermoplastic synthetic resin,preferably a polyamide of a nylon type such as polymerized laurolactam,Grilamid, Polyamide 12 (1 25 W 40 ) or an at least partially aromaticpolyamide. being the most preferred material as it has particularlydesirable smoothness and resistance to temperature and stability toaging;

(2) the number of the perforations is at least 15 and preferably about20 per meter of the spraying zone,

(3) the thickness of the wall tube is from about 0.8 to 2.5 mm;

(4) the distance between two adjacent windings of the helix is about 10to 20 cm; and/or

(5) the diameter of the helix winding is about 75 to 100 cm.

Polyamid 12 and Grilamid are marketed by Ems-Chemie AG, Zurich,Switzerland.

The above-described specific dimension ranges were found by me to becritical in attaining the desired sauna-effect.

Such dimensions were not found in earlier publications none of whichdescribe shower systems for hydrotherapy. Thus, none are given in GermanOffenlegungsschrift 24 32 126 to Wichman, which discloses an apparatusfor spraying a patient's body, or a part of his or her body, inparticular the extremities, with a device having a plurality of sprayingorifices. The apparatus is destined to produce itinerant, variableliquid rays in zones whose configurations are described as disks orcolumns, by switching the admission of liquid to the individual zones bymeans of adjustable valves associated with the zones, such variation tobe dependent on changes in a patient's pulse rate and other bodyproperties. Chambers of sickle or half-moon shaped cross section are,for instance, superimposed in zones, and patterns of spraying orificesdirect the liquid jets to a center in each zone. The half-moon diskchambers are to be steered to wander upward and/or downward along atreated member of the patient's body, travel between an elbow joint andthe finger-tips of the same arm, or between the knee cap and the ankleof a patient's leg being specifically mentioned. A sauna-effect is notenvisaged and, consequently, no specific arrangement or dimensions aregiven to achieve the same.

Specific dimensions are given for a multiple jet fluid spraying systemdescribed in U.S. Pat. No. 3,727,841 to Hengesbach. The looped tubes tobe used in the Hengesbach system are to be extruded from clear celluloseacetate butyrate having an outside diameter of 9.4 mm (3/8") and aninside diameter of 7.8 mm (5/16"). Tubes of 42' (12.60 m) are to beperforated at a spacing, between adjacent orifices, of 15 cm (6"), andeach orifice having an internal width of 0.5 mm to 0.8 mm.

I made comparative tests with hoses made from polyamide 12 (12 carbonatoms between each amido group), because cellulose acetate butyrate istoo unelastic to produce helices of the above-stated critical dimensionsfrom the same. It must be taken into consideration that the Hengesbachconfigurations are limited to wide areas or straight hose pieces.Moreover, I found that polyamide 12 has satisfactory resilience formaking helices, avoiding the danger of kinking which occurred frequentlywhen trying to bend a cellulose acetate butyrate tube to adopt a helixconfiguration for the shower system according to the invention.

COMPARATIVE TESTS

In order to show the criticality of the features stated above, testswere made

A. with a tubular helix within the definitions of claim 1 of the instantapplication;

B. with a tubular helix of the same type as used in Test A., but withthe perforation spacing as disclosed by Hengesbach; and

C. a tubular helix in which all Hengesbach dimensions were observed.

    ______________________________________                                               Tubular helix according to                                                                 Adaptation to                                                                             Hengesbach                                                        perforations of                                                                           (U.S. Pat. No.                                Feature: Claim 1    Hengesbach  3,727,841)                                    ______________________________________                                        1.  Internal  16    mm    16    mm    8     mm                                    width of                                                                      tube                                                                      2   length                                                                        of helix  18    m     18    m     13    m                                 3.  internal                                                                      width of                                                                      perfora-                                                                      tion      0.8   mm    0.8   mm    0.8   mm                                4.  spacing                                                                       between                                                                       two ad-                                                                       jacent                                                                        perfora-                                                                      tions     5     cm    15    cm    15    cm                                ______________________________________                                    

These comparative tests have shown that a sauna effect as described bythe applicant on page 6 of the specification can only be obtained withthe helix according to the applicant's invention and that manifestly theinternal width of the hose forming the helix, the length of the hose andthe distance between two successive perforations in the hose, i.e., thenumber of perforations per meter are critical in achieving the desiredeffect. A sauna effect demands, for instance, that the user transpires.This requires a water temperature of 43° C. or higher. This can indeedbe achieved in the case of the applicant's helix. Test persons havesupported 44° and 46° C. with the novel helix, while a person taking ashower in a helix of the dimensions disclosed as optimal by Hengesbach(U.S. Pat. No. 3,727,841) will not support a higher water temperaturethan 38° C. or at most 40° C.

Moreover, if the shower is turned on to normal strength, the water jetsexert on the body of the showering person a very unpleasant needle pointeffect, which is only supported for a very brief period. When thestrength of the water jets was reduced to avoid this needle pointeffect, the water flowed out of the perforations in the hose accordingto the Hengesbach dimensions at such a low rate that it began to dripdown from the hose windings. The water rate could not be fine-tuned toachieve a readily supportable jet free from the needle point effect.

When a hose of the dimensions taught by me is modified, in accordancewith Hengesbach's teachings to have the perforations at a distance of 15cm (6 inches), the needle point effect is somewhat weaker, but stillunpleasant. Temperatures of 40° C., insufficient to attain a saunaeffect could be supported by test persons for a short time only.

The above-described shower installation can be equipped with liquid flowcontrol means and/or with temperature adjusting means for manuallyadjusting the flow rate and/or the temperature of the liquid beingsprayed out of the perforations of the helix. These liquid flow controland/or temperature adjusting means are preferably arranged relative tothe helix so as to be reachable by a person standing or sitting in theinternal helix space.

Surprisingly, a person standing or sitting in the internal helix spaceof the above-described shower installation, being sprayed from all sidesby the fine sprays from the perforated conduit means according to theinvention, supports water temperatures of 40° C. and considerably higherwhich such person could consider unsupportably hot, when a hot sprayfrom a conventional shower having nozzle openings punched or pierced ina circular shower area impinges on a limited area of his or her skin.

The mantle of hot liquid uniformly covering the body of a person usingthe shower installation according to the invention at a watertemperature above 40° C., e.g. 42° to 45° C., causes in the body of thatperson a long-lasting feeling of well being until such person begins totranspire. After a short intermediary cooling-off period, this treatmentcan be repeated.

As it is possible to replace the small water volume of a giventemperature in the helix very rapidly by water of a differenttemperature, it is easy to use the shower installation according to theinvention for taking an alternating hot and cold bath.

While, under a conventional shower, a considerable proportion of thewater from the water jets, due to their size, is reflected from theskin, the water from very fine jets of the helical shower installationaccording to the invention largely remains on the skin, thus affording ahigher degree of efficiency of the energy consumed in heating the water.

The quality of the therapeutical treatment offered by the helical showerinstallation according to the invention can be further enhanced ordiversified by admixing suitable adjuvants with the water being sprayed.These adjuvants can be costly perfumes or the like because the waterconsumption by the novel shower installation is very restricted, e.g.from 120 to 180 liters during 10 minutes of treatment while a full bathin a bath tub requires about 200 to 400 liters of water.

It is very convenient, if the temperature adjusting means such as ahot-and-cold water mixing valve can be reached by the person taking theshower in standing or sitting position. Intermediary showering with coldwater thus becomes possible without having to leave the installation asone must do in a sauna.

The thickness of the tube wall of the elongated conduit means of theliquid-spraying system according to the invention preferably ranges from0.8 to 2.5 mm, it is preferably considerably greater than the thicknessrecommended for the perforated water trickling hose described bySumitomo Chemical Co. Ltd. in German Offenlegungsschrift 28 35 117.

The production of the perforations having the above described propertiesrequired for achieving a satisfactory spraying of liquid by the sprayingsystem according to the invention, in the elastically resilient extrudedtube wall material which is needed for attaining all of the objects ofthe invention, meets with certain difficulties, which are notencountered when producing similar perforations in metal tubing.

Piercing the perforations with the aid of a fine needle leads to theformation of burr on the internal tube wall surface which obstructs theflow of liquid from the conduit interior into the perforation in anirregular manner. Piercing with heated needles leads to adhesion of thesoftened tube wall material to the needles and an irregular perforation.

Preferably the perforations are made by punching the freshly extrudedmaterial as it passes through a helix-bending machine.

Instead of boring the perforations of capillary size, it is alsopossible to punch larger holes and then insert nozzles having thedesired capillary diameter. Nozzles can be of any suitable material,e.g. hard synthetic resin material as the tubular conduits, glass or asuitable metal such as V₂ A steel.

The perforations are preferably small enough to produce capillary forcesbetween water and the material of the surrounding tube wall sufficientto substantially prevent water filling the conduit interior from flowingout of the perforations while the water in the conduit interior is underambient pressure, but being sufficiently large and of such configurationas to permit ejection of the liquid jet substantially free fromtrickling, when the liquid in the conduit interior is under excesspressure at least of the magnitude derived from a water main. Excesspressure in the water main fluctuates between 0.3 and 1.5 bar.

When the pressure source, e.g. the water main to which the liquidfeeding means are connected is turned off, the liquid remaining in theconduit interior should preferably be held back by the capillary forcesactive in the perforations due to their size and configuration, and tothe interface tension between the liquid and the surrounding tube wallmaterial. These capillary forces should be at least strong enough sothat no more than a trickle of liquid should slowly emerge from theperforations, for instance when the spraying zone of the conduit meanstube wall is very long, e.g. 10 to 20 meters or more and extends invertical position, the number of perforations then being at least 150 to300 or more.

It is important for achieving close to optimal results satisfying theobject of the instant invention that the perforations have a capillarydiameter, i.e. that they open to eject a liquid jet, only when theconduit interior is connected to a low excess pressure source such as awater main, or to a similar source delivering another liquid at apressure at least in the same range as that of the water main.

OBJECTS AND SUMMARY OF A SECOND PARTICULAR ASPECT OF THE INVENTION

It is an object according to another particular aspect of the inventionto provide a novel extractor apparatus and a novel method ofliquid-liquid extraction, making use of the above-described novelspraying system according to the invention.

The conduit means described hereinbefore, and also the helicalembodiment thereof have been found most suitable for use in thefractionated extraction that can be employed for the separation of mixedreaction products, the recovery of useful substances from waste waters,the separation of physically and/or chemically closely relatedsubstances, and the extraction by spraying of vegetable substances or ofinorganic substances such as ores.

It is well known that liquid-liquid extraction techniques provide forthe extraction of a liquid from a solution by intimate contact of thatsolution, preferably in a countercurrent manner, and usually in anextraction column, which is equipped with mechanical means for promotingintimate contact of the first-mentioned solution with another liquidphase in which one or more components of the first solution are readilysoluble, and which second liquid phase, becoming a solution of at leastone of the components of the first solution, must be immiscible, or havea wide immiscibility gap, with the solvent of the first solution. Byrepeated and intimate contact of the first and second solution, andcollecting vessels at such contact zones, a heavy-phase solutioncontaining part of the solute components, and a light-phase solutioncontaining the other part of such components will separate in twodifferent layers, one of which can then be removed from the other.

Among the known liquid-liquid extraction techniques, a modern one hasbeen described in U.S. Pat. No. 4,305,907 to Baird, and involves use ofan extraction column, in which column a light-phase liquid and aheavy-phase liquid are intimately mixed in a counter-current direction,equipped with timing controls for sequentially pulsing the light andheavy phases and controlling the operation of the valves which introduceinto the withdrawel valves from the column the liquid phases based onthe proportions in percent of phase-volume changes occurring in theliquid-liquid extraction in the column. Thereby, the liquid-liquidinterfaces in the column are maintained substantially constant. Thisrequires considerable control equipment, for instance interface controlmeans positioned at one or several interfaces in the column to detect achange in position of the liquid-liquid interface during operation ofthe column as well as another timing device in communication with theinterface control means and with the first timing means to adjust thefirst mentioned timing means, which control the introduction andwithdrawel of the light and heavy phases and the respective solutions,responsive to the detected interface position, so as to maintain theinterface in substantially the same position throughout the extractingoperation.

One of the drawbacks of this known liquid-liquid extraction system isthe occurrence of phase-change volume depletion, and the need forspecial equipment to avoid such occurrence.

In another known liquid-liquid extraction apparatus described byYoichiro Ito, in British Pat. No. 1,553,005, continuous countercurrentextraction is carried out in a rotating array of helical separationtubes made from Teflon through which a heavy-phase and a light-phaseliquid are passed consecutively in a continuous countercurrentoperation.

The tubes are unperforated and each has a length of about 5 metershaving about 100 windings. The throughput is about 0.075 to 0.75 literand the output is about 10 to 100 mag per hour. The apparatus servesmainly for the extraction of very small amounts of biological materialsuch as L-leucyl-L-turosine and other similar peptides (see alsoChemical & Engineering News, Mar. 21, 1983).

It would not be possible to substantially enlarge the Ito apparatusbecause they would require wider tubes, and this would result inreduction of the extraction effect, because the two streams of liquidwould largely pass each other in the coils in spite of the rotation ofthe latter, in view of the inertia of the liquids. Intermingling of theliquids would be insufficient. Also, the rotation of larger tubes mightcause emulsions thus preventing separation of the phases.

It is, therefore, an object of the second aspect of the invention toprovide a liquid-liquid extractor apparatus which is of simpleroperation and less complicated construction than the known apparatus.

It is another object of the second aspect of the invention to provide amethod of liquid-liquid extraction which is easier and less costly tocarry out in practice than the hitherto known methods.

It is a further object of this aspect of the invention to provide anapparatus and method for liquid-liquid extraction which is free from thepossibility of phase-change volume depletions occurring during theoperation, so that special equipment and measures to avoid suchdepletions can be dispensed with.

It is yet another object of this aspect of my invention to provide anapparatus for liquid-liquid extraction which is energy-saving and freefrom rotating parts, having especially stationary extraction tube means.

It is still a further object of this invention to provide an apparatusand a method for liquid-liquid extraction which would permit acontinuous countercurrent iterative extraction.

These objects are attained in accordance with the second inventionaspect by providing a novel liquid-liquid extractor apparatus in which alight-phase liquid and a heavy-phase liquid are intimately mixed in acolumn to provide for the extraction of a solute from one of the phasesby the other phase, which apparatus comprises:

(a) a first conduit for liquid-liquid extraction which has two conduitends one of which is closable and the other is open;

(b) feeding means connected to the open end of this first conduit, forintroducing one of the light-phase and heavy-phase liquids, which lattercontains therein solute to be extracted by the light-phase liquid, intothe interior of the first conduit,

(c) a second conduit having two ends one of which is closable and theother is open;

(d) second feeding means connected to the open end of the secondconduit, and being adapted for introducing the other one of the twobeforesaid liquids into the interior of the second conduit, and

(e) each of the first and second conduits has a hollow interiorextending from one end of the respective column to the other, andcomprises a tube wall of liquid-tight, elastically resilient material,being non-swelling in contact with water of a temperature of 60° C. orhigher and with organic extraction solvents, which tube wall surroundsthe said elongated conduit interior and has an external and an internaltube wall surface; and

this first conduit comprises

(f) a large number of uniform perforations and substantially circularcross-sectional area, which perforations lead from the conduit interiorof the first conduit through the tube wall of the first conduit into thehollow interior of the second conduit; and

the second conduit comprises

(g) a large number of uniform capillary active perforations ofsubstantially circular cross-sectional area through the tube wall of thesecond conduit leading from the conduit interior of the second conduitto outside the external tube wall surface thereof,

all of the perforations of the first and second conduits being of suchconfiguration and width that, when the interior of the second conduit isfilled with liquid under a pressure above the ambient one, theperforations of the second conduit will permit ejection of liquid fromthe interior of the second conduit to the outside as a fine liquid jet,and when the interior of the first conduit is filled with a liquid underpressure above that prevailing in the second conduit, the perforationsof the first conduit will permit the ejection of liquid from theinterior of the first conduit into the interior of the second conduit.

The pressure in the second conduit must, of course, be sufficient toovercome the resistance to the ejection of liquid therefrom due to thecapillary activity of these perforations and the interface tension ofthe liquid.

In a preferred embodiment of the liquid-liquid extractor apparatusaccording to the second invention aspect, the first conduit and thesecond conduit are arranged parallel with one another and comprise acontact zone in which the tube wall of the first conduit is merged withthe tube wall of the second conduit, and the perforations in this zoneof the tube wall of the first conduit lead from the interior of thefirst conduit into the interior of the second conduit.

In another, most preferred embodiment of this second invention aspect,the first conduit is mounted in the interior of the second conduit,constituting a double tube comprising an inner and an outer conduit asthe first and second conduits, surrounding a common longitudinal axisand having concentric cross-sectional areas.

Preferably, the double tube has the configuration of a helix, thewindings of which enclose a helix interior having a central helix axis.The perforations in the tube wall enclosing the second, outer conduitare so disposed therein as to direct the jets ejected through themtoward the central helix axis, describing ballistic curves.

The double tube can also have the configuration of a serpentine.

The liquid-liquid extractor apparatus can further comprise a pluralityof collecting vessels associated with different stages comprising adetermined number of the perforations of the second conduit and arrangedin axial direction along the second conduit to collect the liquidejected from the perforations of each of the said stages, respectively.

Preferably, the liquid-liquid extractor apparatus further comprises aplurality of separator units of which each unit is connected to acollecting vessel, each separator unit comprises a chamber for separatedheavy-phase liquid and a chamber for separated light-phase liquid, aswell as first pipe line means connecting the chamber for light-phaseliquid with that one of the first and second conduits which is fed withlight-phase liquid, and second pipe line means connecting the chamberfor heavy-phase liquid with the other one of the first and secondconduits which is fed with heavy-phase liquid, in the same zone of thesaid first and second conduits in which the perforations of the secondconduit are located from which the liquid jets collected in thecollecting vessel connected with the respective separator unit have beenejected.

In accordance with the second aspect of the invention there is alsoprovided a novel method of liquid-liquid extraction of at least onesolute dissolved in a first liquid being a solution of the solute in asolvent therefore, which method comprises the steps of

(a) directing a stream of the first liquid through a first elongatedchannel from an entry end toward a terminal end of the first channel,and maintaining in the first channel a determined pressure aboveambient,

(b) directing a stream of a second liquid of different density,counter-currently to the first liquid stream, through a second elongatedchannel from an entry end toward a terminal end of the second channel,and maintaining in the second channel an excess pressure lower than thepressure in the first channel,

the first and second channels having longitudinal axes, and one of thefirst and second liquids being the heavier, and the other the lighterone,

(c) maintaining between the first and second channels, a separating wallzone of liquid-tight elastically resilient material being substantiallynon-swelling when in contact with water having a temperature of 60° C.or higher, or when in contact with organic extraction solvents, whichwall zone has a first and a second contact surface on opposite sidesthereof, which surfaces border on the first and second channels,respectively, extending parallel with the axes of the said channels;

this wall zone contains a plurality of crosswise passages therethroughfrom the first to the second contact surface, which passages aredistributed uniformly along the said wall zone in axial direction;

(d) passing a large number of streams of the first liquid, ejected fromthe first channel through the said passages successively into the secondchannel, and intermingling the first liquid streams thereincross-currently with the stream of second liquid flowingcountercurrently through the second channel, while at the same timemaintaining the exit end of the first channel at least substantiallyobturated, thereby maintaining in the first channel a determinedpressure above the pressure prevailing in the second channel, andmaintaining the exit end of the second channel obturated,

(e) ejecting a large number of fine liquid jets of the resulting liquidmixture iteratively out of the second channel, transversely to thedirection of liquid flow through that channel;

(f) collecting groups of the ejected liquid jets, from successiveejection zones of the second channel,

(g) settling the portions of the liquid mixture, obtained from suchzones, with phase separation,

(h) separating the resulting heavier and lighter phases of each liquidportion from each other,

(i) back-feeding the separated heavier phase of a liquid portion from anintermediate zone of the second channel, into approximately the samezone, but of that channel which contains the stream of the heavierliquid, and

(j) back-feeding the lighter phase of a liquid portion from anintermediate zone of the second channel, into approximately the samezone of that channel which contains the stream of the lighter liquid;

(k) recovering from that ejection zone last preceding the terminal endof the second channel one of the phases resulting from the separation ofthe liquid portion collected from that zone, and back-feeding the otherphase into the said first channel, in the same, last-mentioned ejectionzone.

In a preferred mode of operation, one of the two streams is an annularstream having a hollow longitudinal space in its interior, and the otherstream is directed countercurrently thereto through the said hollowinterior of the first-mentioned stream.

Preferably, the annular stream is a stream of heavy-phase liquid and theother stream is a stream of light-phase liquid. The annular stream ofheavy-phase liquid can be directed from a higher level downward to alower level, and the stream of light-phase liquid is directed throughthe interior of the annular stream, but from the lower level upward tothe higher level, and preferably, the two streams follow a helical path.That channel through which the heavier one of the liquids is directed,is preferably filled with granules, inert toward the liquids, forinstance with beads of Teflon PFA or glass.

Preferably, at least a major portion or all of the volume of thelight-phase liquid consists of a light-phase solvent, and at least amajor portion of the volume of the heavy-phase liquid consists of aheavy-phase solvent, which light-phase and heavy-phase solvents aretotally immiscible with one another, or are miscible with each otheronly with an immiscibilty gap.

The apparatus and method according to the invention are particularlyuseful when two solute components having very similar solubility in agiven heavy-phase solvent, have a slightly more different solubility inthe light-phase solvent or viceversa.

Such components can be fatty acids, acids, derived from resin, peptides,proteins, insulin produced with the aid of bacteria, m-cresol andp-cresol, heavy water and normal water, and many others (see "Difficultseparations by extraction" by E. G. Scheibel, published in ChemicalEngineering Progress, supra).

The foregoing as well as other objects and advantages of the presentinvention and the particular aspects thereof will become apparent byreference to the following detailed description thereof with referenceto the accompanying drawings which illustrate, by way of example,preferred embodiments of installations according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a perspective view of a preferred embodiment of a showerinstallation according to the invention,

FIG. 2 is a schematic representation of a first embodiment of aliquid-liquid extractor according to the invention,

FIG. 3 is a perspective partial view of another embodiment of anextractor according to the invention,

FIG. 4 is a perspective partial view of a third embodiment of anextractor according to the invention,

FIG. 5 is a partially sectional view of an extraction system accordingto the invention comprising a fourth embodiment of an extractoraccording to the invention together with a number of collectors,

FIG. 6 is a cross sectional view of the extractor embodiment shown inFIG. 5, and

FIG. 7 is a schematic view, partially in section of an extraction plantcomprising an extractor system according to the invention which containsa fifth embodiment of an extractor.

DETAILED DESCRIPTION OF THE EMBODIMENTS SHOWN IN THE DRAWINGS

The embodiment of a shower installation according to the invention asshown in FIG. 1 comprises a hose 1 of polyvinyl chloride having a nylonfiber reinforcement. The hose is preferably 15 m long and has a circularcross sectional area having an internal diameter of 15 mm. The hose islaid in the shape of a helix having a top ring 2 and a bottom ring 3 aswell as six intermediate coil windings 11, with a pitch of about 15 cm.Vertically extending nylon strings which are suspended from the top ring2 hold the windings in position as a helix.

The ring 2 is preferably suspended from a bathroom ceiling or a frame(not shown) by means of suspension cords or rods 4. By means of aconnecting inlet socket 7, a water-supply tube 5 is connected to a tap10 of the water main and the other end of tube 5 is connected by meansof a hose coupling 8 to the upper end of the hose 1. The hose coupling 8is firmly attached to the upper ring 2. The level of the helical hose 1above the floor can be altered by lengthening or shortening thecorrespondingly devised suspension cords or rods 4.

On the side 11a of the windings 11 which faces toward the central spacedefined by them, the hose 1 is provided with perforations 12 which havebeen produced with a 2, 1mm or better drill at distances of about 5 cmfrom each other, resulting in 20 perforations per meter, or 300distributed uniformly over the entire length of the hose 1. The lowerend 9 of the last winding 11 of the hose 1 is attached to the lower ring3 and closed, for instance by a ligature or stopper (not shown). Anoutlet valve (not shown) can be provided at this end 9, in order toempty the hose 1 rapidly when not used.

The sprays 18 which are ejected from the perforations 12 have been shownin the second loop 11 of the hose, counting from the bottom end.

A person standing or sitting in the helix space inside the windings 11will be hit about 300 fine jets whose points of impingement will bedistributed over his entire body.

If in lieu of the tap 10, there is installed a temperature adjustinghot-and-cold water valve, then a person taking a shower inside the helixcan easily reach such valve and adjust the temperature of the water, forinstance changing rapidly from 40° C. to 10° C. and back, thus attainingthe hydrotherapeutically valuable effect of an alternating hot-and-coldbath or of a sauna.

As a hot water reservoir is usually kept at a water temperature of 50°to 60° C., the user can go as high above 40° C. as he finds supportableuntil he begins to transpire.

In order to get in or out of the internal helix space the lower ring 3can be lifted on one side high enough to enter the internal space orleave it comfortably.

It is also possible to lead the supporting cords 4 over an overheadroller (not shown) and attach a sand bag or the like counter weight totheir free end. The helix can then be raised or lowered without effortas desired.

This type of spraying system can also be used, for instance, for theextraction of finely ground plant material or the like which is movedupward and/or downward along the central helix axis, as desired, and theextraction medium being a mixture produced by the fine jets from bothhoses 1 and 20 coalescing on the surface of the material to beextracted, flows downwardly and is gathered by collector means (notshown) in the bottom zone of the system underneath both hoses. The twophases are then separated in a conventional manner, and processedfurther to recover the different solutes contained therein.

In FIGS. 2 to 7 there are illustrated various embodiments of the novelextractor according to the invention. In all of these embodiments thereare required two tubes having the perforations and other featuresdescribed hereinbefore as being characteristic of the instant invention.In one of the tubes, a heavy-phase liquid, preferably containing amixture of solutes the components of which are to be separated from oneanother, is conveyed in a first direction, while in the second tube alight-phase solvent of the abovementioned properties is conveyed,preferably in countercurrent mode to the heavy-phase liquid.

In the first embodiment of such an extractor, shown in FIG. 2, a firsthelical conduit 1 as illustrated in FIG. 1 is used as the first tube anda second similar helical conduit 19, of a smaller diameter, but mostconveniently of equal length is used as the second tube and is placed inthe internal space within the windings 11 of the first tube. Theperforations 12 of the first tube 1 and the perforations (not shown) ofthe second tube 19 are both arranged in the same manner as shown in FIG.1 and direct their jets toward a middle zone surrounding the commoncentral longitudinal axis of both helices.

In the embodiments shown in FIGS. 3 and 4 the two tubes are arranged inparallel, in the embodiment of FIG. 3 are glued together by a cementbead 21 along the zone in which the outer surfaces of their tube wallstouch. Perforations 22 of the novel type described hereinbefore areprovided to penetrate from a left-hand tube 25 to the right-hand tube 26through the contact zone 27 of both tubes. In the tube 26, there isprovided another row of perforations 28.

Alternatively, as shown in FIG. 4, the two tubes 25' and 26' can beproduced as an integral body 29, for instance by extrusion and areprovided with the same perforations 22 through the common wall zone 27',and 28 in the wall zone of tube 26', opposite the perforations 22.Preferably, the tube containing the perforations 28 leading to theoutside is filled with granules or beads, preferably made of glass orTeflon PFA, i.e. polyperfluoro-alkoxyethylene, marketed by E. I. DUPONTDE NEMOURS, Wilmington, Del. or similar suitable material inert tochemicals occurring in liquid-liquid extraction.

The preferred operation of the embodiments shown in FIGS. 3 and 4comprises the steps of passing a heavy-phase solute containing liquidpreferably through the tube 26 or 26' and most preferably from the upperto the lower end of the tube when the latter is in inclined or verticalposition. It is also possible to arrange the tubes in serpentine shape.

At the same time, a light-phase liquid is passed through the tube 25 or25' at an at least slightly higher pressure than prevails in the tube 26or 26'. Thereby light-phase liquid will penetrate through theperforations 22 from the interior of tube 25 into the interior of tube26 (or correspondingly from the interior of tube 25' into the interiorof tube 26') and will intermingle therein with the heavy-phase liquid. Amixture of heavy-phase and light-phase liquids in which some componentsof the solute have passed from the heavyphase to the light-phase is thenejected in jet form.

In the embodiment of a liquid extractor according to the invention, adouble hose 100 comprises an inner tubular conduit 101 shown in FIG. 5or 6, which is surrounded by a tube wall 102 ofpoly-(perfluoroethylene-propylene(Teflon FEP, manufactured by E. I.DuPont de Nemours, (supra) as the elastically resilient material. Theinner conduit 101 is surrounded by an outer tubular conduit 110 which isin turn enclosed in an outer tube wall 111. In the tube wall 102, thereare provided a large number of perforations 104 for example 20 permeter, each of which has perferably a diameter of about 0.6 mm, producedby boring through the tube wall 102 with a twist drill having a bitdiameter of 0.7 mm.

The outer tube wall 111 is likewise provided with a large number ofperforations 112. The amount of liquid to be ejected through theseperforations 112 from the annular interior of the outer conduit 110 mustbe large enough so that there can be accommodated in the zone in which agiven number of perforations 104 and 112 is provided, the amount ofliquid added from the entry end of the conduit 110 plus the amount ofliquid injected into that zone from the inner conduit 101 through theperforations 104. The annular space in the outer conduit about the tubewall 102 is preferably filled with granules 105 of Teflon PFA (supra)which favor intermingling of the liquid flowing through the outerconduit 110 with the liquid from the inner conduit 101 injected throughthe perforations 104. Moreover, it reduces the flow rate of the liquidstream through this conduit 110.

For instance, when, in a given section of the double hose 100 the ratioof the volume of the inner conduit to that of the outer conduit is 1:2,and the outer conduit has 50% of its volume occupied by the aforesaidgranules, so that the effective volume ratio is 1:1, and when the numberof the inner perforations 104 is equal to the number of the outerperforations 112, then it is suggested that the cross sectional area ofthe outer perforations 112 be approximately twice the cross-sectionalarea of the inner perforations 104. When the inner perforations wereobtained by boring with a twist drill as defined above, resulting in across sectional area of each perforation 104 of 1.13 mm², then,perforations 112 having each a cross sectional area of 2.25 mm², i.e. adiameter of about 0.85 mm, can be obtained by boring them with a twistdrill having a bit diameter of 1 mm.

With the double hose 100 there is associated a number of collectorsegments vessels 115 to 118 at different levels and overlapping oneanother in order for each segment to catch a group of jets.

Given a length of the double hose 100 of 15 meters and 20 perforations112 per meter, there will result 300 jets, which are collected in groupsof 10 to 15 jets, requiring 20 to 30 collector segments.

The further processing of the collected quantities of liquid will bedescribed hereinafter in connection with the embodiment shown in FIG. 7.

In FIG. 7 there is illustrated schematically a liquid-liquid extractionplant comprising a helix-shaped double tube conduit 120.

When built with the same dimensions as employed in the embodiment of ahelix-shaped tube in FIG. 1, the conduit 120 will have in its outer tubewall 111 a total of 300 perforations 112. The pitch of the windings ofthe helix-shaped conduit 120 has been exaggerated in FIG. 7 for the sakeof greater clarity. As in FIG. 1 the pitch would be about 15 cm when thediameter of the helix windings, taken radially with regard to thelongitudinal central helix axis is about 75 cm.

The build-up of the double tube 120 is the same as in FIGS. 5 and 6 andlike parts in FIGS. 5 to 7 are designated by like numerals. The portionof each helical winding situated in front of the paper plane isindicated by dashed lines, and the perforations 112 therein by dottedlines, while the rear sections are shown in full lines. While the lengthof the double tube 120 and the diameter, stated above, of such windingaffords a number of six and one half windings, of which only four,namely windings 121, 122, 123 and 124 are shown in FIG. 7; one and ahalf of these windings are shown in the upper part, and two and a halfwindings in the lower part of the plant shown in that Figure. Eachwinding thus has a length of about 2.30 meters and contains 46 of thetotal of 300 perforations; of these 46 perforations only a few have beenshown.

In a region about the axis of the helix interior, there are mountedseveral collector vessels of which only six are shown. Actually, if acollector vessel is provided for every three to six liquid jets directedfrom perforations 112 toward the central region of the helix, then therewill be required one hundred to fifty such collector vessels in asomewhat different arrangement placing the dishes at points on anarrower helix of a pitch proportionate to that of the helix-shapedconduit 120, i.e. parallel with and slightly below that conduit at theinside thereof.

In practice, the spacing of these collector vessels inwardly from thewindings of the conduit 120 will be such that the impingement of a groupof three to six jets adjacent each other on the floor of the respectivecollector vessel is assured.

In FIG. 7 only six such collector vessels 31 to 36 have been shown, andhave been arranged along the helix axis for the sake of clarity.

The uppermost vessel 31 has an outlet connected via a pipe 31a to themiddle zone of a separator unit 41. Corresponding to the number ofcollector vessels there is a separator unit 42 to 46 connected to eachcollector vessel 32 to 36 via pipes 32a to 36a.

The separator unit 42 has been shown enlarged on the right-hand side ofFIG. 7. All other separator units have the same structure, but have beenindicated only schematically.

The separator unit 42 comprises a lift pump 47 which pumps the liquidmixture via a valve 48 from the vessel 32 into a funnel-shaped reservoir49 and from there via a three-way valve 51 into an upper and a lowerseparator vessel 55 and 56 which are connected with each other via ashut-off cock 57. The upper separator vessel 55 is further equipped witha reservoir 50 for light-phase solvent with a pressure meter 52 in apipe line 50a, leading into the vessel 55 from the reservoir 49 via thethree-way valve 52.

Likewise, the separator vessel 56 is equipped with a heavy-phase solventreservoir 53 from which heavy-phase solvent can be bled into the lowerseparator vessel 56 via a pressure meter 54 and a shut-off valve 58.

The light-phase contents of the upper separator vessel 55 can be fedback via a line 60 and valve 61 into the same zone of the inner conduit101 of the helical double tube winding 122 from which the liquid jetsare being ejected that fill the collector vessel 32, while theheavy-phase contents of the lower separator vessel 56 can be fed backvia a line 62 and valve 63 into the outer tubular conduit 110 of theaforesaid helical double tube winding 122 in the same zone.

At the upper end of the uppermost double tube winding 120, there areprovided a reservoir 65 of heavy-phase liquid from which that liquid canbe fed continuously by means of a pump 66 into the outer conduit 110,while a valve 67 permits discharge of the residual unseparated mixturefrom the inner conduit 101, and offers access to that conduit forcleaning, e.g. by injection of a cleaning fluid.

From the uppermost collector vessel 31 which is disposed a shortdistance from the upper end of the helical double tube 120, e.g. toreceive three or six of the ejected jets of liquid mixture from thefirst winding 121, the collected liquid passes through line 31a which isequipped in a similar manner as line 32a in the separator unit 42, intothe separator unit 41, but while the heavy-phase liquid which separatedout in the lower separator vessel 41a is fed back via a line 160 intothe outer conduit 110 of the same winding 121, the light phase gatheredin the upper separator vessel 41b of this uppermost unit is conveyed bya suitable lift pump (not shown) into an evaporator 67 in which thesolute contained in this light-phase liquid is recovered while thelight-phase solvent vapors can be recovered in a condenser 68.

From the lowermost collector vessel 36 the collected liquid mixture isfed into the separator 46, from where the supranatant light phase in theupper separator vessel 46b is fed back into the inner conduit 101 in thesame zone of winding 124 from which liquid was ejected from the outerconduit 110 into the collector vessel 36. The heavy phase obtained inthe separator vessel 46a is conveyed through a line 166 to an evaporator70 in which the solute of the heavy phase liquid is recovered, while theheavy phase solvent is recovered in a condenser 71.

Fresh light phase solvent can be delivered from a reservoir 72 thereforevia a feed line 73 and with the aid of a pump 74 into the lower end ofthe inner conduit 101. Residual heavy phase waste liquid not gathered inthe collector vessel 36 can be discharged from the outer conduit 110 viaa discharge valve 75, through which a cleaning fluid can also beinjected into the conduit 110 after the same has been emptied fromextraction liquid.

The apparatus and the method for liquid-liquid extraction according tothis aspect of my invention as described hereinbefore affords acontinuous countercurrent distribution involving an iterativeextraction, in which a combination of cross-current and countercurrenttechniques is employed.

The fact that all elements of an extraction plant according to myinvention are stationary with the exception of pumps, the consumption ofenergy in the whole plant can be kept at a minimum.

Moreover, the extraction tube means are most simple and inexpensive toconstruct as compared with complicated columns in the prior artrequiring the mounting of a number of baffles in an extraction tower,which in term requires interface control in order to prevent depletion.There is no danger of depletion in operating my novel extraction plant.

Another drawback of the known extraction apparatus operating withcolumns in which the two phases pass through superimposed chambersseparated by perforated baffles or sieves is that the formation ofemulsions will occur easily and these emulsions will then pass fromchamber to chamber without having time during the process to separateagain into their phases before they reach the end of the column. Incontrast thereto, if emulsion occurs in any zone of my double tubes, theportion of liquid which contains the emulsion is promptly ejected inseveral successive jets into one or several collector vessels and passedon from there to a reservoir or to a separator unit before being fedback into the extraction double tube. Thus, the emulsion in such ejectedliquid portions has ample time to separate again into its phases.

Another important advantage of my novel liquid-liquid extractionapparatus and method resides in the fact that the volumes of theseparated phases which have to be processed further to recover thedesired solutes are much smaller than those obtained from comparableextraction methods such as described by Baird.

Thus, separations by solvent extraction described by E. G. Scheibel inChemical Engineering Progress (Vol. 62, No. 9 of Sep.1966) requirescontinuous removal of about 25% of the total operating liquid for thepurpose of evaporation and recovery of the solute and solvent. In myprocess it is possible to carry out this evaporation and recovery withsmall fractions of liquid separated phases amounting to as little as 5%of the total volume of liquid in circulation in the plant.

This requires correspondingly smaller recovery units and correspondinglyless energy consumption per time, especially when taking into accountthat the losses due to disturbing factors such as depletion oremulsification can be completely avoided in my method and apparatus.

I claim:
 1. A method of liquid-liquid extraction of at least one solutedissolved in a first liquid being a solution of said solute in a solventtherefor, comprising the steps of(a) directing a stream of said firstliquid through a first elongated channel from an entry end toward aterminal end of said first channel, and maintaining in said firstchannel a determined pressure above ambient, (b) directing a stream of asecond liquid of different density, counter-currently to said firstliquid stream, through a second elongated channel from an entry endtoward a terminal end of said second channel, and maintaining in saidsecond channel a pressure lower than said pressure in said firstchannel,said first and second channels having longitudinal axes, and oneof said first and second liquids being the heavier, and the other thelighter one, (c) maintaining between said first and second channels, aseparating wall zone of liquid-tight elastically resilient materialbeing substantially non-swelling when in contact with water having atemperature of 60° C. or higher, or when in contact with organicextraction solvents, said wall zone having a first and a second contactsurface on opposite sides thereof, which surfaces border on said firstand second channels, respectively, extending parallel with the axes ofsaid channels;said wall zone containing a plurality of crosswisepassages therethrough from said first to said second contact surface,said passages being distributed uniformly along said wall zone in axialdirection, (d) passing a large number of streams of said first liquid,ejected from said first channel through said passages successively intosaid second channel and intermingling said first liquid streams thereincross-currently with said stream of second liquid flowingcountercurrently through said second channel, while at the same timemaintaining said exit end of said first channel at least substantiallyobturated, thereby maintaining in said first channel a determinedpressure above the pressure prevailing in said second channel, andmaintaining said exit end of said second channel obturated, (e) ejectinga large number of fine liquid jets of the resulting liquid mixtureiteratively out of said second channel, transversely to the direction ofliquid flow through said second channel; (f) collecting groups of saidliquid jets, from successive ejection zones of said second channel, (g)settling the portions of the liquid mixture, obtained from such zones,with phase separation, (h) separating the resulting heavier and lighterphases of each liquid portion from each other, (i) back-feeding theseparated heavier phase of a liquid portion from an intermediate zone ofsaid second channel, into approximately the same zone, but of thatchannel which contains the stream of the heavier liquid, and (j)back-feeding the lighter phase of a liquid portion from an intermediatezone of said second channel, into approximately the same zone of thatchannel which contains the stream of the lighter liquid; (k) recoveringfrom that ejection zone last preceding the terminal end of said secondchannel one of said phases resulting from the separation of the liquidportion collected from said zone, and back-feeding the other phase intothe said first channel, in said last-mentioned ejection zone.
 2. Themethod of claim 1, wherein at least a major portion or all of the volumeof said light-phase liquid consisting of a light-phase solvent, and atleast a major portion of the volume of said heavy-phase liquidconsisting of a heavy-phase solvent, said light-phase and heavy-phasesolvents being miscible with an immiscibility gap or being totallyimmiscible with one another.
 3. The method of claim 2, wherein one ofsaid streams is an annular stream having a hollow longitudinal space inits interior, and that the other stream is directed countercurrentlythereto through said hollow interior of said firstmentioned stream. 4.The method of claim 3, wherein said annular stream is a stream ofheavy-phase liquid and the other stream is a stream of light-phaseliquid.
 5. The method of claim 4, wherein said annular stream ofheavy-phase liquid is directed from a higher level downward to a lowerlevel, and the stream of light-phase liquid is directed through theinterior of said annular stream, but from said lower level upward tosaid higher level.
 6. A liquid-liquid extractor apparatus in which alight-phase liquid and a heavy-phase liquid are intimately mixed in acolumn to provide for the extraction of a solute from one of the phasesby the other phase, which apparatus comprises:(a) a first conduit forliquid-liquid extraction, said conduit having two conduit ends, one ofwhich is closable and the other is open; (b) feeding means connected tosaid open end of said first conduit, for introducing one of saidlight-phase and heavy-phase liquids containing therein solute to beextracted by the other liquid into the interior of said first conduit,(c) a second conduit having two ends one of which is closable and theother is open; (d) second feeding means connected to said open end ofsaid second conduit, and being adapted for introducing the other one ofsaid light-phase and heavy-phase liquids into the interior of saidsecond conduit, (e) each of said first and second conduits having ahollow interior extending from one end of the respective column to theother; and comprising a tube wall of liquidtight, elastically resilientmaterial, being non-swelling in contact with water of a temperature of60° or higher and with organic extraction solvents, said tube wallsurrounding said hollow elongated conduit interior and having anexternal and an internal tube wall surface; andsaid first conduitcomprising (f) a large number of uniform perforations of substantiallycircular cross-sectional area, said perforations leading from saidconduit interior of said first conduit through the tube wall of saidfirst conduit into the hollow interior of said second conduit; andsaidsecond conduit comprising (g) a large number of uniform capillary activeperforations of substantially circular cross-sectional area through saidtube wall of said second conduit leading from said conduit interior ofsaid second conduit to outside said external tube wall surface thereof,all of said perforations of said first and second conduits being of suchconfiguration and width that, when said interior of said second conduitis filled with liquid under a pressure above the ambient pressure, saidperforations of said second conduit will permit ejection of liquid fromthe interior of said second conduit to the outside as a fine liquid jet,and when said interior of said first conduit is filled with a liquidunder pressure above that prevailing in said second conduit, saidperforations of said first conduit will permit the ejection of liquidfrom the interior of said first conduit into the interior of said secondconduit.
 7. The liquid-liquid extractor apparatus of claim 6, whereinsaid first and second conduits are arranged parallel with one anotherand comprise a contact zone in which said tube wall of said firstconduit is merged with said tube wall of said second conduit, and saidperforations in said tube wall of said first conduit lead from theinterior of said first conduit into the interior of said second conduit.8. The liquid-liquid extractor apparatus of claim 6, wherein said firstconduit is mounted in the interior of said second conduit, constitutinga double tube comprising an inner and an outer conduit as said first andsecond conduits, surrounding a common longitudinal axis and havingconcentric cross-sectional areas.
 9. The liquid-liquid extractorapparatus of claim 8, wherein said double tube has the configuration ofa helix, the windings of which enclose a helix interior having a centralhelix axis.
 10. The liquid-liquid extractor apparatus of claim 9,wherein the perforations in the tube wall enclosing said second, outerconduit are so disposed therein as to direct the jets ejected throughthem toward said central helix axis, describing ballistic curves. 11.The liquid-liquid extractor apparatus of claim 6, further comprising aplurality of collecting vessels associated with stages consisting of adetermined number of said perforations of said second conduit andarranged in axial direction along said second conduit to collect theliquid ejected from the perforations of each of said stages,respectively.
 12. The liquid-liquid extractor apparatus of claim 11,further comprising a plurality of separator units of which each unit isconnected to a collecting vessel, each separator unit comprising achamber for separated heavy-phase liquid and a chamber for separatedlight-phase liquid, first pipe line means connecting said chamber forlight-phase liquid with that one of said first and second conduits fedwith light-phase liquid, and second pipe line means connecting saidchamber for heavy-phase liquid with the other one of said first andsecond conduits being fed with heavy-phase liquid, in the same zone ofsaid first and second conduits in which the perforations of said secondconduit are located from which the liquid jets collected in thecollecting vessel connected with said separator unit have been ejected.